The present invention relates broadly to the protection of particulate materials from erosion and water infusion. More specifically the invention is directed to the application of a surface coating agent to the surface of particulate materials to effect water and wind resistance.
Wind erosion of exposed masses of particulate matter such as coal, ore, and mine mill tailings causes both air pollution and economic waste. Detrimental effects on health and cleanliness of the home result when these fine particles are carried aloft on the winds. When valuable minerals are eroded, economic loss may be substantial.
Water causes undesirable effects both by erosion and by water infusion which would lead to undesired caking of particles into bulky masses which are hard to convey. Conveying methods are impeded by the size of these cakings. For example, the unloading of railroad coal cars through their hopper doors is often made virtually impossible by caking of the coal so extensive as to block the openings in the base of the hopper.
One approach employed to prevent wind erosion is the use of a device known as a water buggy, which sprays water on the dry areas of the accumulation. The operation is very expensive and may lead to the agglomeration problem noted above.
Silicone resins have been used to reduce water absorption and to improve adhesion and resistance to weathering of concrete walls and drives, ceramic and stone surfaces, asphalt, foam and mat insulation, glass beads, asbestos shingles, and decorative tile.
These silicone resins have not been successfully applied to mineral piles, particularly those of carbonaceous matter. The surfaces of these piles contain loose material which is subject to water and wind erosion. Silicone resins applied to reduce water absorption do not bind these loose particles together. The treated surface is therefore subject to erosion which removes the silicone coated particles thereby destroying the ability to reduce water absorption.
U.S. Pat. No. 2,854,347 shows the use of elastomeric substances such as synthetic polymers in latex form to coat the surfaces of minerals.